How do i force www subdomain on both https and http - apache

Question

For whatever reason I can't seem to get this right, I've looked at many examples on here and apache's website. I'm trying to force www.domain.com instead of domain.com on EITHER http or https but I am not trying to force https over http.
the following code seems to work for all https connections but http will not redirect to www.
RewriteEngine On
RewriteCond %{HTTPS} on
RewriteCond %{HTTP_HOST} !^www\.domain\.com$ [NC]
RewriteRule ^ https://www.domain.com%{REQUEST_URI} [R=301]
RewriteEngine On
RewriteCond %{HTTPS} off
RewriteCond %{HTTP_HOST} !^www\.domain\.com$ [NC]
RewriteRule ^ http://www.domain.com%{REQUEST_URI} [R=301]

Answer 1

You don't need the second RewriteEngine directive. That may or may not be causing a parse issue making the second set of rules not work. To test whether this is the case, try switching the order of the two blocks you have.
It's good practice to use L to modify requests that are definitely the last. So, change [R=301] to [R=301,L] both times it appears.
Largely as a matter of style, I would consider changing the RewriteRule directives to something like (using http or https as appropriate):
RewriteRule ^(.*)$ http://www.domain.com$1 [R=301,L,QSA]

Answer 2

Your rules seem to be fine. You can combine them as follows:
RewriteCond %{HTTP_HOST} !^www\.example\.com$
RewriteCond %{HTTPS}s on(s)|
RewriteRule ^ http%1://www.example.com%{REQUEST_URI} [L,R=301]
Also note the additional L flag to stop the rewriting process after this rule has been applied.

Answer 3

In case anyone still need an answer to this. Use another .htaccess. Get guide from here, I found it and it looks good: http://www.farinspace.com/codeigniter-htaccess-file/
<IfModule mod_rewrite.c>
RewriteEngine On
RewriteBase /
### Canonicalize codeigniter URLs
# If your default controller is something other than
# "welcome" you should probably change this
RewriteRule ^(welcome(/index)?|index(\.php)?)/?$ / [L,R=301]
RewriteRule ^(.*)/index/?$ $1 [L,R=301]
# Removes trailing slashes (prevents SEO duplicate content issues)
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule ^(.+)/$ $1 [L,R=301]
# Enforce www
# If you have subdomains, you can add them to
# the list using the "|" (OR) regex operator
RewriteCond %{HTTP_HOST} !^(www|subdomain) [NC]
RewriteRule ^(.*)$ http://www.domain.tld/$1 [L,R=301]
# Enforce NO www
#RewriteCond %{HTTP_HOST} ^www [NC]
#RewriteRule ^(.*)$ http://domain.tld/$1 [L,R=301]
###
# Removes access to the system folder by users.
# Additionally this will allow you to create a System.php controller,
# previously this would not have been possible.
# 'system' can be replaced if you have renamed your system folder.
RewriteCond %{REQUEST_URI} ^system.*
RewriteRule ^(.*)$ /index.php/$1 [L]
# Checks to see if the user is attempting to access a valid file,
# such as an image or css document, if this isn't true it sends the
# request to index.php
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule ^(.*)$ index.php/$1 [L]
</IfModule>
<IfModule !mod_rewrite.c>
# Without mod_rewrite, route 404's to the front controller
ErrorDocument 404 /index.php
</IfModule>
Remember, once you have your CodeIgniter htaccess file setup, you will want to go into your “/system/application/config/config.php”, find the following:
$config['index_page'] = "index.php";
and change it to:
$config['index_page'] = "";